1. Field of the Invention
The present invention relates to a light irradiating device for generating radiation from an LED light source, which enhances cell-mediated immunity. Also, the present invention is concerned with a method for enhancing cell-mediated immunity using the same.
2. Description of the Related Art
In humans, immunity, representative of the hallmarks of health, may be greatly weakened by excessive exercise, stress, and other factors.
An improvement in immunity allows the body to more easily surmount stress and to become healthy. In fact, immunopotentiation prevents the body from being infected with pathological microorganisms such as bacteria, fungi, viruses, etc. and, in the case of infection, helps the body overcome diseases and return to the healthy state.
Various studies have been done on the regional or systemic effects of visible light on the body, and thus far, lots of results have been reported concerning neonatal jaundice, improvement of microcirculation, promotion of wound healing, pain relief, control of circadian rhythms, etc.
For this reason, light therapy using visible light has recently become a new trend in natural medicine.
It was not until the late 1980s that light therapy attracted intensive attention thanks to the possibility of being a new alternative medicine. Since then, this medical field has made great progress. It is now widely known that light, whether natural or artificial, has a significant influence on one's usual states of feeling and of mind as well as physical and mental health. For instance, LLLT (low level light therapy) with low-frequency, narrow-band radiation has been proven helpful for pain relief and wound healing.
Studies on the relationship between visible light and immunity may be summarized as follows.
A division of immunity is characterized by the cells involved: humoral immunity is the aspect of immunity that is mediated by B-lymphocytes secreting antibodies such as immunoglobulins whereas the protection provided by cell mediated immunity involves T-lymphocytes acting most significantly.
Visible light has an influence on both of the divisions of immunity.
Irradiation with light in the wavelength range of UV elicits immune reactions mainly at the skin. Because UV light, short in wavelength, cannot penetrate the dermis layer, it mostly acts to suppress cell-mediated immunity at the skin.
On the other hand, visible light ranging in wavelength from 380 to 780 nm penetrates through the epidermis and the dermis to the vessels millimeters distant from the skin surface, so that it can be used to induce photoreactions in blood as well as the irradiated spot.
Samoilova et al. (2004) showed that visible light, unlike UV light, induces blood cells to experience structural and functional changes which are immediately transmitted to entire circulating blood pools through vessels.
Zhevago et al. (2004) reported that exposure to visible light alters immunoglobulin levels in blood with a sharp increase in the levels of IgM and IgA.
According to Kubasova et al. (1995), irradiation with a combination of low-energy density visible light and infrared light was observed to induce the formation of lymphoblasts.
Mach et al. (1999) focused on the effect of visible light on wound healing, reporting that T lymphocytes, responsible for cell-mediated immunity, play an important role in the visible light-induced wound healing.
Based on results from a histological examination on the skin exposed to 630 nm visible light for 8 hours, Takezaki et al. (2006) reported the gathering of T lymphocytes to the exposed skin region.
Visible radiations, although within the same wavelength range, differ from one another in properties depending on wavelength bands. In photodynamic therapy, in fact, visible light is used to potentiate or suppress immunity depending on the wavelengths thereof and the combined use of a sensitizer.
For reference, showing immunosuppressive properties, the UV light UVA or UVB is used for therapy for contact dermatitis or delayed hypersensitivity.
Taken together, results from previous studies indicate that the biological functions of light are determined by its wavelengths and irradiation energies.
Leading to the present, invention, intensive and thorough research into light therapy using visible light, conducted by the present inventors, resulted in the finding that visible light within a specific single wavelength band activates the structure of proteins involved in the activation of T lymphocytes responsible for cell-mediated immunity and that the visible light with the specific wavelength shows far higher immunopotentiation than typical visible light.
The visible light used in the present invention is quite different from the light used in conventional low level light therapy in terms of wavelength band, light coherency and energy density. Whereas the low level light therapy with low-frequency narrow-band light has an influence on the irradiated spot only, the light therapy using the light irradiating device of the present invention enhances cell-mediated immunity which is effected across the whole body.